Comments that include profanity or personal attacks or other inappropriate comments or material will be removed from the site. Additionally, entries that are unsigned or contain "signatures" by someone other than the actual author will be removed. Finally, we will take steps to block users who violate any of our posting standards, terms of use or privacy policies or any other policies governing this site. Please review the full rules governing commentaries and discussions. You are fully responsible for the content that you post.

What does it take to determine which of the world's 9,800 bird species depend on fresh water for survival? Try devoting two months' worth of evenings and weekends to reading the descriptions of every known avian species, which is what Timothy Boucher did.

"Being a fanatic birder, I decided this could be really fun," recalled Boucher, a senior conservation geographer at the Nature Conservancy who has personally seen and identified 4,257 species of birds in his life. So his "life list," as birders say, covers 43 percent of the bird species that exist.

The result of Boucher's work -- a map showing the wetlands and rivers on which 828 freshwater bird species depend -- is part of the Atlas of Global Conservation, a new publication that shows how nature is faring across the globe.

Environmental researchers evaluate the state of nature in a number of ways -- by listing the most imperiled species, focusing on particular habitats or detailing the pace of human activities that transform the planet. But mapmaking, which provides a visual account of how different ecological regions are faring, provides one of the most easily accessible ways of depicting of the global environment.

The atlas is the work of eight scientists at the Nature Conservancy who three years ago set out to chart everything from the mangroves in Borneo where proboscis monkeys live to the extent of grasslands on Mongolia's steppes, in order to produce 80 detailed maps.

"The atlas is telling us what's where, what state it's in, what people are doing to it now -- the big threats, and what we can do to turn it around," said senior marine scientist Mark Spalding of the Conservancy.

The maps -- all done on the same scale -- depict a dizzying array of ecosystems, plants and animals across the globe in different stages of depletion. One shows how the human demand for water outstrips the natural supply in dry and crowded regions such as the American West and the Mediterranean basin; another shows how large areas of intact forests cover 10 percent of the earth's land surface, while they once spread over nearly half of it.

"The sobering message shouldn't be glossed over," said Boucher. He added that since maps showing where animals are threatened also show that some are surging back to health, "It's a case of sorrow, but also a case of hope."

Eric Sanderson, a senior conservation ecologist at the Wildlife Conservation Society, said one of the most significant aspects of the book is that it crosses the three types of habitats that exist: terrestrial, freshwater and marine.

"They're literally covering a hundred percent of the world with the datasets," Sanderson said, adding that while his group focuses on species, the atlas sheds light on how the eco-regions of the world are faring. "It's really important that we conserve not just the places with the most species, which tend to be in the tropics, but conserve places across the gradient of nature."

Evaluating the state of the world's habitats and the living creatures that inhabit them amounts to a daunting task. In order to obtain the level of detail they needed, the atlas's authors delved into centuries-old archives as well as Google maps, and tapped into the work of 70 institutions worldwide. In some cases they sought out experts in Russia, Latin America and Asia who could guide them.

In other cases, finding the right mathematical equation was essential. The Nature Conservancy's senior terrestrial scientist, Michael Jennings, created a map titled "Into the Wild" that examines the impact of increasing human access to remote areas. To do that he relied on a model developed by the Swedish army that estimates how hunters and gatherers move across the landscape, along with a report that calculated how much effort it takes farmers in developing countries to get their products to market.

While the project began as an internal planning exercise for the Conservancy, which has established a goal of conserving 10 percent of the world's nature by 2015, Boucher said the group is now using its mapmaking to inform members of the public "so they really understand what they're doing to our planet, and then figure out what we can do to change it."

For all of the atlas's stark images of environmental degradation -- such as one showing the many causes of amphibians' decline -- it also hints at the possibility of recovery with maps charting protected areas that cross international borders.

"We have the technology. We have the tools, we have the mechanisms, the ideas, the plans to turn things around," Spalding said. "We can turn things around."